Trials Show Tight Glucose Control Pays Dividends in CVD Reduction Years Later

June 14, 2005

Bonnie Darves

June 14, 2005 (San Diego) Intensive therapy early on in the course of diabetes continues to pay big dividends in reducing cardiovascular disease (CVD), nearly two decades after it is initiated, researchers reported here at the American Diabetes Association's (ADA) 65th Annual Scientific Sessions.

Nearly two decades after the start of the Diabetes Control and Complications Trial (DCCT), participants who had type 1 diabetes and received intensive therapy to treat their diabetes continue to achieve major health benefits a 42% reduction in risk of cardiovascular disease and a 57% reduction in serious CVD-related events such as myocardial infarction, stroke, and death.

"We think this finding is a 9 on the Richter scale," said David Nathan, MD, Harvard University professor of medicine and cochair of the DCCT Epidemiology of Diabetes Interventions and Complications (EDIC) follow-up study of 1,375 volunteers. "The findings likely will inform future diabetes prevention and treatment efforts, Dr. Nathan said, because 93% of the original DCCT participants, most of whom were in their twenties when that trial was begun, are now in middle age, when complications such as CVD begin to occur. "This indicates that if intensive therapy is begun early and maintained, the very serious complications [of diabetes] may be reduced significantly. I expect to see life spans [increase] further with long-term intensive control."

In the DCCT/EDIC participants, those who received what was considered "conventional" therapy at the time (the mid to late 1980s) have fared less well than their more aggressively treated counterparts, who received six years of intensive glucose control. In the EDIC study, those conventionally treated individuals experienced 98 CVD events, compared with 46 in the intensively treated group. At the study's completion in 2004, participants' average age was 43 years.

"The main message here for clinicians is that starting good glucose control early may prevent some of the very serious complications of diabetes," said Allen Spiegel, MD, director of the National Institute of Diabetes and Digestive and Kidney Diseases. Despite the positive findings, Drs. Spiegel and Nathan were reluctant to say whether the results suggest that target hemoglobin A1c measures should be lowered, for the purposes of deciding when to initiate intensive therapy or when to make a confirmed diagnosis of diabetes. "The point is that in our population of type 1 patients, lowering glycemia appears to be important forever because a 10% lowering of A1c was equated with a 21% reduction in cardiovascular disease," Dr. Nathan said.

ADA's Chief Scientific and Medical Officer Richard Kahn, PhD, concurred. "This reduction [in CVD events] with tight [glucose] control is better than we see in statins," Dr Kahn said.

ADA 65th Annual Scientific Sessions: Late-breaking clinical trials session. Presented June 12, 2005.

Reviewed by Gary D. Vogin, MD

Bonnie Darves is a freelance writer for Medscape.


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